Design of a hybrid electric fuel cell power train for an urban bus

With the requirements for reducing emissions and improving fuel economy, new markets have become attractive for automotive companies that are developing electric, hybrid, and plug-in vehicles using new technologies candidates to be implemented in the next generations of vehicles. Most of all, hybrid vehicles are attracting interest due to great potential to achieve higher fuel economy and a longer range with respect to pure electric mode but often this solution is not petroleum free. Within a national project CNR TAE Institute is involved in the development of a zero emission hybrid electric city bus based on PEM fuel cell technology able to increase the range at least 30% with respect to the same vehicle in pure electric configuration. Design, control and preliminary results are reported in this paper.     

The fuel cell electric vehicles: The highlight review

Transportation sector is the important sector and consumed the most fossil fuel in the world. Since COVID-19 started in 2019, this sector had become the world connector because every country relies on logistics. The transportation sector does not only deal with the human transportation but also relates to logistics. Research in every country has searched for alternative transportation to replace internal combustion engines using fossil fuel, one of the most prominent choices is fuel cells. Fuel cells can use hydrogen as fuel. Hydrogen can be fed to the fuel cells to provide electric power to drive vehicles, no greenhouse gas emission and no direct combustion required. The fuel cells have been developed widely as the 21st century energy-conservation devices for mobile, stationary, and especially vehicles. The fuel cell electric vehicles using hydrogen as fuel were also called hydrogen fuel cell vehicles or hydrogen electric vehicles. The fuel cells were misconceived by several people that they were batteries, but the fuel cells could provide electric power continuously if their fuel was provided continuously. The batteries could provide electric power as their only capacities, when all ions are released, no power could be provided. Because the fuel cell vehicles play important roles for our future transportation, the overall review for these vehicles is significantly interesting. This overall review can provide general and technical information, variety of readers; vehicle users, manufacturers, and scientists, can perceive and understand the fuel cell vehicles within this review. The readers can realize how important the fuel cell technologies are and support research around the world to drive the fuel cell vehicles to be the leading vehicles in our sustainable developing world.     

Fuel cell/battery passive hybrid power source for electric powertrains

The concept of passive hybrid, i.e. the direct electrical coupling between a fuel cell system and a battery without using a power converter, is presented as a feasible solution for powertrain applications. As there are no DC/DC converters, the passive hybrid is a cheap and simple solution and the power losses in the electronic hardware are eliminated. In such a powertrain topology where the two devices always have the same voltage, the active power sharing between the two energy sources can not be done in the conventional way. As an alternative, control of the fuel cell power by adjusting its operating pressure is elaborated. Only pure H₂/O₂ fuel cell systems are considered in this approach. Simulation and hardware in the loop (HIL) results for the powertrain show that this hybrid power source is able to satisfy the power demand of an electric vehicle while sustaining the battery state of charge.     

Model-based power control strategy development of a fuel cell hybrid vehicle

An integrated procedure for math modeling and power control strategy design for a fuel cell hybrid vehicle (FCHV) is presented in this paper. Dynamic math model of the powertrain is constructed firstly, which includes four modules: fuel cell engine, DC/DC inverter, motor-driver, and power battery. Based on the mathematic model, a power control principle is designed, which uses full-states closed-loop feedback algorithm. To implement full-states feedback, a Luenberger state observer is designed to estimate open circuit voltage (OCV) of the battery, which make the control principle not sensitive to the battery SOC (state of charge) estimated error. Full-states feedback controller is then designed through analyzing step responding of the powertrain and test data. At last of the paper, the results of simulation and field test are illustrated. The results show that the power control strategy designed takes into account the performance and economy characteristics of components of the FCHV powertrain and achieves the control object excellently.     

Experimental investigation of fuel cell dynamic response and control

An experimental study of the dynamic response of a commercial fuel cell system is presented in this work. The primary goal of the research is an examination of the feasibility for using fuel cells in a load-following mode for vehicular applications, where load-following implies that the fuel cell system provides the power necessary for transient responses without the use of additional energy storage elements, such as batteries or super-capacitors. The dynamic response of fuel cell systems used in the load-following mode may have implications for safe and efficient operation of vehicles. To that end, a DC–DC converter was used to port the power output of the fuel cell to a resistive load using a pulse-width-modulating circuit. Frequency responses of the system were evaluated at a variety of DC offsets and AC amplitudes of the PWM duty cycle from 1 out to 400 Hz. Open-loop transient responses are then evaluated using transitions from 10% to 90% duty cycle levels, followed by dwells at the 90% level and then transitions back to the 10% level. A classical proportional–integral controller was then developed and used to close the loop around the system, with the result that the fuel cell system was driven to track the same transient. The controller was then used to drive the fuel cell system according to a reference power signal, which was a scaled-down copy of the simulated power output from an internal combustion engine powering a conventional automobile through the Federal Urban Driving Schedule (FUDS). The results showed that the fuel cell system is capable of tracking transient signals with sufficient fidelity such that it should be applicable for use in a load-following mode for vehicular applications. The results also highlight important issues that must be addressed in considering vehicular applications of fuel cells, such as the power conditioning circuit efficiency and the effect of stack heating on the system response.     

Fuel cell vehicles: State of the art with economic and environmental concerns

Hydrogen fueled fuel cell vehicles (FCVs) will play a major role as a part of the change toward the hydrogen based energy system. When combined with the right source of energy, fuel cells have the highest potential efficiencies and lowest potential emissions of any vehicular power source. As a result, extensive work into the development of hydrogen fueled FCVs is taking place. The aim of this paper is to highlight some of the research and development work which has occurred in the past five years on fuel cell vehicle technology, with a focus on economic and environmental concerns. It is observed that the current efforts are divided up into several parts. The performance, durability, and cost of fuel cell technology continue to be improved, and some fuel cells are currently ready to be mounted on vehicles and tested. Environmental and economic assessments of the entire hydrogen supply chain, including fuel cell end-use, are being carried out by groups of researchers around the world. It is currently believed that fuel cells need at least five more years of testing and improvement before large scale commercialization can begin. Economic and environmental analyses show that FCVs will likely be both economically competitive and environmentally benign. Indeed, the transition of the transportation sector to the use of hydrogen FCVs will represent one of the biggest steps toward the hydrogen economy.     

Evaluation of a platinum leasing program for fuel cell vehicles

This paper evaluates the feasibility of a platinum leasing program for future fuel-cell vehicles (FCVs) in the United States. By internalizing the residual value of platinum in the vehicle's upfront cost, a platinum lease may offer cost savings to the consumer. Several leasing scenarios were evaluated to estimate potential cash savings.     

The clean energy partnership Berlin—CEP

The clean energy partnership (CEP) is an international cooperation comprising 11 energy and technology companies as well as car manufacturers (Aral/BP, BMW, Berliner Verkehrsbetriebe (BVG), Daimler, Ford, GM/Opel, Hydro, Linde, TOTAL, Vattenfall Europe and Volkswagen AG). The vision of mobility based on hydrogen is commonly shared by the partners. The objective of the CEP is to prove everyday suitability of hydrogen for transportation purposes by real-life operation of hydrogen stations integrated into conventional filling stations, by efficient and reliable hydrogen vehicles in customer operation and by fast, convenient and safe fuelling of vehicles with liquid an gaseous hydrogen.     

Innovative design of an hydrogen powertrain via reverse engineering

In this paper the powertrain of a zero emission vehicle powered by hydrogen has been designed with an innovative approach via reverse engineering.The use of a zero environmental impact vehicles is particularly stringent in urban area where high air pollutant concentrations could be reached. In particular, in this paper, the use of fuel cell vehicles plus ultracapacitors has been considered to minimize the TTW (Tank to Wheels) global efficiency in comparison with the conventional vehicles powered by ICE.A zero emissions city-car is designed by optimization of the components (in particular the energy storage) in order to minimize both its weight and its bulk with particular reference to the functions (passenger vehicles, minibus, freight distribution), the areas where the vehicle is driven (characteristic drive cycles, traffic) and the users (different driving style). In particular the design discussed in this paper was carried out through a process of reverse engineering. The energy needs, in fact, were calculated starting from real drive cycles obtained during an on-board data acquisition campaign carried out in Rome urban area.In this paper the powertrain is designed starting from the acquisition of real drive cycles obtained during acquisitions campaign in an urban area. The data collected by the on-board acquisitions systems has been used to evaluate the power required by the wheels as a function of time in a generic urban drive cycle and the energy needs of an urban vehicle. Thus, the analysis performed takes into account not only global energy consumption, but also the power needs that are affected by both the congested traffic conditions and the driving style.     

Hydrogen economy for a sustainable development: state-of-the-art and technological perspectives

Sustainable energy is becoming of increasing concern world-wide. The rapid growth of global climate changes along with the fear of energy supply shortage is creating a large consensus about the potential benefits of a hydrogen economy coming from renewable energy sources. The interesting perspectives are over-shadowed by uncertainties about the development of key technologies, such as renewable energy sources, advanced production processes, fuel cells, metal hydrides, nanostructures, standards and codes, and so on. The availability of critical technologies can create a base for the start of the hydrogen economy, as a fuel and energy carrier alternative to the current fossil resources. This paper will explore the rationale for such a revolution in the energy sector, will describe the state-of-the-art of major related technologies (fuel cell, storage systems, fuel cell vehicles) and current niche applications, and will sketch scientific and technological challenges and recommendations for research and development (R&D) initiatives to accelerate the pace for the widespread introduction of a hydrogen economy.     

Test of hybrid power system for electrical vehicles using a lithium-ion battery pack and a reformed methanol fuel cell range extender

This work presents the proof-of-concept of an electric traction power system with a high temperature polymer electrolyte membrane fuel cell range extender, usable for automotive class electrical vehicles. The hybrid system concept examined, consists of a power system where the primary power is delivered by a lithium ion battery pack. In order to increase the run time of the application connected to this battery pack, a high temperature PEM (HTPEM) fuel cell stack acts as an on-board charger able to charge a vehicle during operation as a series hybrid. Because of the high tolerance to carbon monoxide, the HTPEM fuel cell system can efficiently use a liquid methanol/water mixture of 60%/40% by volume, as fuel instead of compressed hydrogen, enabling potentially a higher volumetric energy density.     

Disruptive innovations: The case for hydrogen fuel cells and battery electric vehicles

The investment of private money in technological innovation is driven by the expectation of successful market penetration. This decision to invest is less risky when the innovation represents gradual improvement of existing technologies. The term disruptive innovation is used to describe the opposite case, i.e. innovations that are so different that their establishment in the market causes a disruption to the pre-existing system. The existing literature on disruptive innovations provides us with historic case studies of successful market capture by new technologies, but this in itself is insufficient to clarify the chances of success for nascent technologies. This paper sets out to bring greater clarity to the characteristics of disruptive innovation in a way that informs the debate on the viability of emerging technologies. Whilst existing definitions are based on technologies that were successful, this paper proposes a three part criteria to define candidate disruptive technologies: disruption should relate to manufacturers and/or infrastructure (the two often being inter-related), whilst innovation must provide more than the equivalence of service to the end-user. A review of seven historical case studies of successful disruptive technologies reveals seven characteristics of candidate disruptive technologies at the stage of niche market penetration. Examining battery electric and hydrogen fuel cell vehicles against these seven characteristics, shows that both candidate disruptive technologies share the same challenges as those identified in the successful historic case studies and also helps to identify potential pathways to greater market penetration in the future for these technologies.     

Analysis of a “cluster” strategy for introducing hydrogen vehicles in Southern California

The cost and logistics of building early hydrogen refueling infrastructure are key barriers to the commercialization of fuel cell vehicles. In this paper, we explore a “cluster strategy” for introducing hydrogen vehicles and refueling infrastructure in Southern California over the next decade, to satisfy California's Zero Emission Vehicle regulation. Clustering refers to coordinated introduction of hydrogen vehicles and refueling infrastructure in a few focused geographic areas such as smaller cities (e.g. Santa Monica, Irvine) within a larger region (e.g. Los Angeles Basin). We analyze several transition scenarios for introducing hundreds to tens of thousands of vehicles and 8–42 stations, considering:     

Optimal power allocation for a FCHV based on linear programming and PID controller

Hybrid electric vehicles positively influence the transportation industry with regards to reducing the use of fossil fuels and minimizing polluting emissions. A class of such vehicles incorporates fuel cells and energy storage systems as alternatives to internal combustion engines. This paper develops a dynamically efficient energy management system for fuel cell hybrid vehicles for the purpose of achieving an optimal power allocation between the energy sources while adhering to component requirements and maintaining the essential operational performance. The paper addresses a two stage control methodologies, pre-driving optimization using linear programming algorithms and on-line optimization using PID controllers and component mechanisms. The performance criteria are based on the overall operational cost as well as the hydrogen consumption per trip. Comparison against a state control algorithm shows improvements in hydrogen consumption.     

Can hydrogen be the sustainable fuel for mobility in India in the global context?

This article provides a critical assessment of H₂ from the standpoint of more widespread use as a sustainable fuel for Indian mobility applications in the global context. The potential techno-economic advantages of utilizing H₂ for automobiles rather than battery electric vehicles or conventional internal combustion engine vehicles are emphasized. The present assessment demonstrates that H₂ production, storage, and distribution costs are the primary challenges, and a significant improvement is still necessary for H₂ to compete either against the internal combustion engine vehicle or the battery electric vehicle to win the race, arguably. The secondary challenges have also been demonstrated, which include the cost of the fuel cell stack and the modifications associated with internal combustion engine vehicles, as well as regulatory and safety concerns, which impede the widespread usage of H₂. It is critical that policy-making for sustainable mobility in India is possible with the aid of a National H₂ Energy Road-Map. This in turn can achieve a cost target of $0.5/kg for H₂.